16-methyl derivatives of progesterone



United States Patent 0 Iii-METHYL DERIVATIVES OF PROGESTERONE Arthur E.Oberster, North Canton, Ohio, and Lewis H. Sarett, Princeton, N.J.,assignors to Merck & Co., Inc., Rahway, N..I., a corporation of NewJersey N0 Drawing. Continuation of application Ser. No.

187,220, Apr. 13, 1962, which is a continuation of application Ser. No.786,024, Jan. 12, 1959, now Patent No. 3,088,951, dated May 7, 1963.This application June 8, 1964, Ser. No. 373,540

1 Claim. (Cl. 260-397.45)

This application is a continuation of our copending application SerialNo. 187,220, filed April 13, 1962, now abandoned, which, in turn, is acontinuation of Serial No. 786,024, filed January 12, 1959, now US. Pat.No. 3,088,951, issued May 7, 1963.

This invention relates to 16-alkyl steroids. More particularly, it isconcerned with 16a-rnethyl derivatives of progesterone and methods ofpreparing these compounds.

In accordance with the present invention, it is now found that certainderivatives of l6u-methyl-progesterone possess valuable pharmacologicalproperties progestational and anti-inflammatory agents.

It is an object of the present invention to provide 90:- fl-uoro-llfi-hydroxy-l6-methyl-progesterone and methods of preparing thiscompound. Another object is to provide9cx-fiuoro-1l-keto-l6ot-methyl-progesterone and a process for thepreparation of this product. A further object is to provide1l-keto-l6a-methyl-progesterone and a method for the preparation of thiscompound. An additional object of this invention is to provideintermediate products useful in the preparation of these new compounds.Other objects will be apparent from the detailed description of thisinvention hereinafter provided.

Pursuant to one embodiment of the present invention, it is now foundthat 11a-hydroxy-l6oc-methyl-progesterone can be converted to9OC-fl-llOI'O-l1finhYdl'OXY-160tmethyl-progesterone and9OL-fillOI'O-11-keIO-16 C-II16thylprogesterone by procedures which maybe shown as follows:

CH CH l l i I II VII 3,288,818 Patented Nov. 29, 1966 wherein Xrepresents a halogen from the group consisting of chlorine and bromine.

In the foregoing process the starting compoundllahydroxy-l6a-methylprogesterone is first reacted with a dehydratingagent to obtain the corresponding diene, A -l6a-methyl-progesterone(II). The reaction of this compound with hypochlorous or hypobromousacid produces the corresponding 9a-halo compound, namely,9ahalo-1lli-hydroxy-l6a-methyl-progesterone (III). When this 9a-halocompound is reacted with an alkali, the 9,11-oxido compound (V) isobtained. Reaction of the latter compound with hydrogen fluoride yields9u-fluoro- 1LB-hydroxy-16a-met-hyl-progesterone (VI). Oxidation of thiscompound with a suitable oxidizing agent affords 9u-fluoro-ll-keto-l6ix-met-hyl progesterone (VII).

In the first step of the above-described process, the starting compoundis reacted with a suitable dehydrating agent to form the corresponding M-compound. Suitable dehydrating agents for this reaction that might bementioned are methylchlorosulfinate, methane sulfonyl chloride and thelike. Alternatively, the dehydration is effected by intimatelycontacting the starting material with N- bromo-acetamide and treatingthe resulting reaction product with sulfur dioxide. In carrying out thedehydration in accordance with another embodiment of this invention, the11u-hydroxy-l6a-methyl-progesterone is intimately contacted with methanesulphonyl chloride in the presence of pyridine at low temperatures toproduce the corresponding lloc-rnesylate. The intermediate product thusobtained is converted to the diene compound by heating with acetic acidfor sufiicient time to effect the dehydration and produce A-16a-methyl-progesterone.

The next step of the process is effected by reacting the A-16u-methyl-progesterone with a hypohalous acid, wherein the halogen hasan atomic weight between 35-80, namely, bromine or chlorine. Thisreaction is most conveniently effected by reacting a suspension orsolution of the diene compound in a suitable Water-miscible solvent suchas acetone with an aqueous solution of the hypohalous acid. Thehypohalous acid solution is conveniently prepared in situ by reactingthe appropriate N-halosuccinimide with perchloric acid. For example, thereaction is very conveniently carried out by adding aqueous perchloricacid to a mixture consisting of a suspension or solution of the dienecompound in acetone and N- bromosuccinirnide.

In the following step of our process the halohydrin (III) is reactedwith alkaline reagents to form the 9,11- oxido compound. This reactionis readily effected by dissolving the halohydrin in a suitable solventsuch as tetrahydrofuran and adding thereto a solution of potassiumcarbonate in water. After completion of the reaction, the produ'ct isrecovered by extracting the reaction 1'' mixture with ethyl acetate orany other suitable solvents.

The next step of our process is carried out by reacting the 9,1l-oxidecompound (V) with hydrogen fluoride. This reaction is preferably carriedout in the presence of a suitable solvent such as tetrahydrofuran or amixture of tetrahydrofuran and chloroform. For the obtainment of maximumyields we find that it is desirable to carry out the reaction at atemperature of about 0 C. For example, the reaction is effected byadding a solution of the 9,11-oxido compound in chloroform to a mixtureconsisting of tetrahydrofuran, chloroform, and hydrogen fluoride at 0 C.After completion of the reaction the reaction mixture is then quenchedby the addition of chloroform, ice and potassium carbonate. Thechloroform layer is then separated and concentrated down to a drynesswhereupon the desired 9u-fluoro-1lp-hydroxy-16a-methylprogesterone isobtained.

The 9a-fiuoro-1lfi-hydroxy-16a-methylprogesterone is readily convertedto the corresponding ll-keto compound (VII) by reaction with a suitableoxidizing agent. For example, this reaction is conveniently effected byoxidizing the 11 B-hydroxy compound with chromium trioxide in thepresence of acetic acid. The product can be recovered from the resultingreaction mixture in accordance with conventional procedures known inthis art.

In accordance with a further embodiment of this invention, it is foundthat the halohydrin (III) can be converted to the corresponding ll-ketocompound by oxida tion of the halohydrin with a suitable oxidizingagent. For example, this is conveniently carried out by intimatelycontacting the 'halohydrin with chromium trioxide in glacial aceticacid.

As indicated above, the new compounds of the present invention possessvaluable pharmacological properties and are useful as progestational oranti-inflammatory agents. Thus,9a-fiuoro-llfl-hydroxy-l6u-methylprogesterone possesses oral andsubcutaneous progestational activity greater than that of 19-norethisterone. The compounds, 9a-fluoro-11;3hydroxy-16a-methylprogesteroneand 90cfiuoro-ll-keto-l6m-methylprogesterone are activeanti-inflammatory agents and possess systemic granuloma activity of 1 to3 times that of hydrocortisone. Also, these compounds and11-keto-16ot-methyl progesterone show liver glycogen activity. The newcompounds of the present invention have the desirable property of beingnonsalt retainers, whereas the non-methylated compounds are saltretainers. These new compounds, therefore, have important advantagesover the products of the prior art.

The following examples illustrate the processes of the presentinvention.

EXAMPLE 1 1 1 u-hydroxy-l Got-me lhyl progesterone 11 a-mesylale I Fourhundred and twenty milligrams of llu-hydroxy- 16ot-methylprogesteronewas dissolved in a solution of 6.4 ml. of pyridine and 2.6 ml. ofmethanesulfonyl chloride at C. The reaction mixture was then warmed toroom temperature and allowed to stand for two hours. The reactionmixture was then added to 10 ml. of ice-water and extracted with 3 x 30ml. of ethyl acetate. The extracts were combined, washed with dilutehydrochloric acid, sodium bicarbonate solution, water, dried andevaporated to dryness resulting in 520 mg. of product. A sample of the1la-hydroxy-16u-methylprogesterone 11amesylate Was recrystallized frommethylene chloride-ether and melted at 174-176 C. (dec.);

use

Analysis-Calculated for C H O S (422.56): S, 7.59.

Found: S, 7.48.

EXAMPLE 2 A -1 6 a-methyl progesterone (II) The11a-hydroxy-16u-methylpr-ogesterone 11u-mesylate (450 mg.) prepared asdescribed in Example 1 was treated with 610 mg. of sodium acetate and 6ml. of acetic acid at reflux for thirty minutes. The reaction mixturewas then cooled, diluted with water and extracted with 3 x 50 ml. ofether. The extracts were combined, washed with sodium bicarbonatesolution, water, dried and evaporated to dryness resulting in 350 mg. ofcrude product. Recrystallization from petroleum ether (B.P. 30-60 C.)resulted in 290 mg. of crystalline A -16a-rnethylprogesterone melting at118-120 C. The product gives a positive color reaction withtetranitromethane.

CHOI; 8X.

4 Analysis.Calculated for C H O (326.46): C, 80.93; H, 9.26. Found: C,80.87; H. 9.04.

EXAMPLE 3 9a-b1'0m0-1 1 5-113 droxy-I 6 ot-methylprogesterone (III) M-16a-methylprogesterone (260 mg.) and N-bromosuccini-mide (218 mg.) weredissolved in 3 ml. of acetone at 0 C. with stirring. To this stirredsolution was added 0.72 ml. of aqueous perchloric acid (0.458 gr. of 70%aqueous perchloric acid in 16.5 ml. of water). The solution remainedhomogeneous for a few seconds and then a white precipitate of productformed. The reaction mixture was stirred at 0 C. for 2 hours. Theproduct was filtered, washed with cold acetone and ether and air dried.The product weighed 290 mg. and melted 177-184 C. (dec.). A sample ofthe 9a-bromo-1l,8-hydroxy-16arnethylprogesterone recrystallized foranalysis from hot acetone melted at 185-188 C. (dec.),

AMBOH Analysis.Calculatedfor C H O Br (423.49): C, 62.41; H, 7.38; Br,18.87. Found: C, 62.61; H, 7.27; Br, 18.97.

EXAMPLE 4 -1 Ifi-oxido-I 6a-methylprogesterone (V) 5.80;.t, 5.98m6.15,!L.

Analysis.-Calculated for C H O (342.46) C, 77.15; H, 8.83. Found: C,76.82; H, 8.60.

EXAMPLE 5 9ot-fluor0-11p-hydr0xy-1 6 a-methylprogesterone (VI) Asolution of 157 mg. of 9fi,11;8-oxido-16u-methylprogesterone in 5 ml. ofchloroform was added to a solution consisting of 2.5 ml. oftetrahydrofuran, 1.8 ml. of chloroform and 3.3 ml. of hydrogen fluoridein tetrahydrofuran (2:1 by weight) at 0 C. The reaction mixture was leftat 0 C. for three hours and then left to warm to room temperature andpoured into a mixture of 25 g. of potassium carbonate, 40 grams ofice-water and 40 ml. of chloroform. The chloroform layer was separatedand the aqueous layer washed with an additional 20 ml. of chloroform.The chloroform extracts were combined, Washed with water, and dried oversodium sulfate. Removal of the solvent resulted in 161 mg. of crudeproduct. Recrystallization from hot acetone resulted in 93 mg. of9ot-fluoro-11fi-hydroxy-l6otmethylprogesterone, M.P. 271-276" C.,

use

Analysis.-Calculated for C H O F (362.47): C, 72.90; H, 8.62; F, 5.25.Found: C, 72.86; H, 8.45; F, 4.88.

EXAMPLE 6 1 1 -keto-1 6 a-methylprogesterone (VIII) To a solution of 500mg. of llor-hydroxy-l6a-methylprogesterone in 8 ml. of glacial aceticacid was added at room temperature a solution containing 150 mg. ofchromium trioxide in 7.5 ml. of 90% aqueous acetic acid. The reactionmixture was stirred at room temperature for 30 minutes. At the end ofthis time, 2 ml. of ethanol was added and the reaction mixtureconcentrated to a syrup under vacuo. The residue was dissolved inchloroform and the chloroform solution was washed with sodiumbicarbonate solution, water and dried over sodium sulfate. Removal ofthe chloroform and recrystallization of the product from methylenechlorideether resulted in 290 mg. of ll-keto-l6oc-methylprogesterone,M.P. 183-186 C.,

H, 8.83. Found: C, 77.02; H, 9.00.

EXAMPLE 7 9a-brom0-I1-ket0-16m-methylprogester0ne (IV) To a solution of500 mg. of 9a-bromo-11fi-hydroxy- 16a-methylprogesterone in 8 ml. ofglacial acetic acid was added at room temperature a solution containing150 mg. of chromium trioxide in 7.5 ml. of 90% aqueous acetic acid. Thereaction mixture was stirred at room temperature for thirty minutes. Twomilliliters of ethanol was added and the reaction mixture concentratedto a syrup under vacuum. The residue was dissolved in chloroform, washedwith sodium bicarbonate solution, water and dried over sodium sulfate.Removal of the solvent and recrystallization from methylenechlorideether resulted in 322 mg. of9a-bromo-11-keto-16amethylprogesterone, M.P. 170l77 C. (dec.),

use 5.80 5.95 6.15

EXAMPLE 8 9auoro-II-keto-16a-methylpr0gester0ne (VII) To a solution of9a-fiuoro-11B-hydroxy-l6a-methylprogesterone (300 mg.) in 4.8 ml. ofglacial acetic acid was added a solution of 90 mg. of chromium trioxidein 4.5 ml. of 90% aqueous acetic acid. After a total reaction time ofthirty minutes, 2 ml. of ethanol was added and the reaction mixture wasconcentrated to a syrup under vacuum. The syrup was dissolved inchloroform, washed with sodium bicarbonate solution, water and driedover sodium sulfate. Removal of the solvent and crystallization of9a-fluoro-11-keto-16a-methy1- progesterone from hot acetone resulted in218 mg, M.P. 185-188 C.;

max.

5.821s, 5.95 L, 6.15,u.

The starting material, lla-hydroxy-l6a-methylprogesterone, used inpreparing the new compounds of the present invention can be prepared asfollows:

7.2 grams of magnesium were overlaid with 125 ml. of anhydrous ether andconverted in the usual way to the Grignard reagent with 45 g. of methyliodide in 125 ml. anhydrous ether. To this Grignard reagent was added0.125 g. of cuprous chloride anhydrous and 13.2 g. of A -pregnenoloneacetate in 425 ml. of anhydrous ether. The ethereal steroid solution wasadded over the course of 1 hour and refluxed for 2 hours after additionwas complete. The cooled reaction mixture was decomposed by the cautiousaddition of 300 ml. of saturated ammonium chloride. The aqueous layerwas separated and extracted with ether. The combined ethereal extractswere washed to neutrality with Water and dried over magnesium sulfate.Evaporation of the ether on the steam bath yielded 8.8 g. of crudel6a-methyl-pregnenolone. The infra-red spectrum of the crudel6a-methyl-pregnenolone indicated complete removal of the acetate group.

One gram of the crude 16a-methyl-pregnenolone prepared above wasdissolved in 140 ml. of acetone distilled from permanganate. Thesolution was cooled to 0-5 C. and 0.9 ml. of chromic acid solution(26.72 g. of chromic oxide and 23 ml. of sulfuric acid diluted to ml.with water) was added all at once. The mixture Was stirred for 5 minutesand poured into 1 liter of water. Then the mixture was placed in arefrigerator for 1 hour, filtered and washed with water. The driedproduct was dissolved in hot methanol and 2 drops of 2.5 N sodiumhydroxide was added and heated on the steam bath for 5 minutes. Thealkali was neutralized with 36% acetic acid and diluted with water. Themixture was placed in a refrigerator, filtered and washed with water.The dried product, 1600- methylprogesterone, had a melting point of116120 C.,

x322 2420, Ey

A medium is prepared having the following composition:

Glucose g 20 An enzymatic lacto-albumen digest (Edamin) -g 20 C-ornsteepliquor ml 5 Water to make 1 liter.

This medium is distributed in 50 ml. portions in appropriate vessels.The pH of the medium is adjusted to 6.5 with 1 M potassium hydroxide andsterilized at 120 C. for 12 minutes.

The medium in each vessel is then inoculated with a heavy aqueoussuspension of spores of a strain of Rhizopus nigrz'cans (American TypeCulture Collection No. 6227b) and the inoculated media are maintained atan incubation of 28 C. for 48 hours on a rotary shaking machine.

Ten mg. of 16a-methylprogesterone prepared as described is added to eachvessel from a dimethyl-formamide soltuion (100 mg./ml.). Thetransformation is allowed to go for an additional 24 hours undeconditions identical to the growth phase. The whole broth is thenextracted 3 times with equal volumes of ethyl acetate, the extractscombined, and finally concentrated. The lla-hydroxy-16a-methylprogesterone is filtered off.

Various changes and modifications of the invention can be made and, tothe extent that such variations incorporate the spirit of thisinvention, they are intended to be included within the scope of theappended claim.

We claim:

Fieser et al.: Pub. Co., NY.

LEWIS GOTTS, Primary Examiner. ELBERT L. ROBERTS, Examiner. HENRY A.FRENCH, Assistant Examiner.

